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Looking to stiffen up the front end a bit. According to the Fairwheel Bikes 2014 stem review the Thompson X4 is the stiffest alloy stem they tested. Anyone have experience with that vs the Deda Zero 100 or the Easton EA90 who can comment on how they compare? I'm running 120 so getting a solid stem is important to me.

Who ever said anything about a loss or gain in power? The OP just said they want to stiffen up the front end, don't see anything wrong with that. It's just personal preference.

Personally I had the Zero 100 SC stem with the ti bolts and though it was plenty stiff, really liked it but had one of the bolts shear off in the stem about a year and a half after I purchased it. Wasn't able to extract it so it's now worthless.Haven't had any experience with the other two but I have the deda superlegerro stem and it is definitely a little softer than the regular zero 100. Oh and both those stems were 130mm and were paired with deda alu bars.Currently I am running the pro vibe sprint stem in 135mm and vibe 7s round bars just because why not have a little fun every once in a while and it's pretty dang stiff. Actually pretty fond of the setup and don't think I'll switch back any time soon. That stem is such a honker though; it's wayyyy bigger than I thought it would be.

Bottom line I would go for either the deda or the Thompson. Personally I don't like Easton stuff for some reason. Maybe because their old hubs were crap and I've had to work on so many and I hated their EC90 aero bars-flexiest I've ever tried but all that is another story.Buy what you like best, I don't think you will be disappointed.

Haven't tried the Thomson. I used to have a 3T ARX, and a Ritchey WCS alloy. I wanted a 10° stem, so changed to a Pro Vibe 7S, I felt it was more "solid" than the 3T, but not that much more than the Ritchey. I just changed to Easton EA90, and went from 120 to 130. Don't feel much difference between them, they're both very solid (to me).

Im running a Thomson X2 - 130mm 10° stem with FSA Omega Compact bars, and its pretty stiff. Did a couple of hard sprints and could not really feel any significant flex. Its a great combination, but i'm also pretty sure that there's some even stiffer combinationts out there, like Pro's Vibe stem with the Vibe bars, as it was mentioned before here.

Valbrona wrote:I am interested in how much power you think you would gain by having a stiffer stem. Or put another way, how much power you think you lose by having a flexy stem.

Hornedfrog hit it on the head; for me it's about handling, not power. I currently have a Deda Zero 100 with Thompson KFC bars, and since I like the shape of the bars I do want to stick with them but would consider changing to another -8 or -10 stem if there would be a noticeable improvement in stiffness from that component.

According to Fairwheel's review the Thompson X4 is the stiffest alloy stem, beating out the Pro Vibe 7s in the deflection metric, with the Pro Vibe 7S having the edge in stiffness to weight ratio. While this is WW, I am open to adding a touch of weight (gasp!) if the stiffness gain would be noticeable.Would be great if someone could give a real-world based comparison of the Deda (currently on my bike) to either the Easton or the Thompson.

Or for aesthetics of matched components, I could just go with the Thompson stem based on the Fairwheel tests... although I'm not going to replace my Syntace HiFlex P6 seatpost with a Thompson....

To the OP...Based on educated guessing...a sprinter, in a sprint may lose 5Watts over a stiff stem.I made that up. But figure the rider is putting out over 1000Watts in a sprint. They are using the bars to transmit energy. The bars are flexing and most the energy is not returned.

So 5w or .05% feels conservative.

For non sprints, I belive the flex to be an asset.Thompson is great product. Own seatpost and stems.

I can attest, although Fairwheel claimed the Shimano Pro Vibe 7S Carbon was the least stiff, I also run the Shimano Pro Vibe Carbon compact bars that are T800 UD, it is a stiff setup, but not overly. I'm a sprinter (900-1000w 20s+ sprint average)...the Scott Foil 15 BB and other parts of the bike are more flexy than that bar/stem combo.

Plus, on a foil, a slight dampening of the bars is appreciated, the ride is so darn brutal on that frame.

Quote from Fair Wheel Bikes "We don’t believe that there is any efficiency to be gained through a stiffer..."Everything on your bike flexes and ~ 2 degrees deflection using the worst stem is not something to worry about.Gotta love reading reviews when riders state "This stem is like a wet noodle..." When I sprint, last thing I do is pay attention to deflection in stem and trying to get a feel for it.

Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

boysa wrote:I have an X4 and love it.... I was using a Deda Zero 100 before, but the Thomson really improved the handling of the bike. As for "sprinting stiffness," I'd be lying if I said I felt much of a difference. Not at my size/power.

Very helpful. Handling is where I hope to see gains from stiffness, and this comparison is exactly what I was hoping from the forum folks here.

mpulsiv wrote:Quote from Fair Wheel Bikes "We don’t believe that there is any efficiency to be gained through a stiffer..."Everything on your bike flexes and ~ 2 degrees deflection using the worst stem is not something to worry about.Gotta love reading reviews when riders state "This stem is like a wet noodle..." When I sprint, last thing I do is pay attention to deflection in stem and trying to get a feel for it.

No quarrel from me; again, for me it's not about power transfer, it's about helping the handling on the front end. I do think that's a different dynamic than efficiency -- efficiency sounds like power transfer to me....